Teaching Case

A 65-year-old female patient presented with a two-week progressive loss of visual acuity and occasional dull pain in the right eye. Ophthalmologic examination was remarkable for best corrected visual acuity (BCVA) of hand motion, retinal pigment epithelium mottling with choroidal folds and an altered macular reflex in the right eye.

Ocular ultrasonography (US) B scan of the right eye revealed a 2,8 mm thick medium reflective dome-shaped lesion encompassing the entire posterior pole with some epilesional subretinal fluid. US A-scan demonstrated medium reflectivity. These findings were indicative of choroidal metastasis (CM).

Enhanced depth imaging optical coherence tomography (EDI-OCT) exhibited dome-shaped retinal elevations with considerable subretinal fluid in the right eye and normal retinal architecture in the left eye.

Magnetic resonance imaging (MRI) of the head demonstrated a well-defined semilunar lesion with a localised retinal detachment at the right posterior globe. The lesion was isointense on T1-weighted images, slightly hyperintense on T2-weighted images and homogeneously enhanced on post-contrast T1-weighted images.

Furthermore, several nodular and ring-enhancing lesions with typical appearance of metastases were observed in the brain. FLAIR and T2-weighted images revealed mild perilesional oedema.

To determine the site of primary carcinoma, additional imaging examination was performed. Chest CT scan demonstrated a pathologic formation in the right lower lobe. Transbronchial biopsy with pathohistological examination revealed the diagnosis of primary lung adenocarcinoma.

Background

Due to its dense vascular supply the choroid is the favoured ocular site for haematogenous disseminated metastases. The most common sites of primary carcinomas are breast and lung in women and lung and gastrointestinal tract in men.

A third of patients with CM have no known history of cancer, and in approximately 10% of the cases no primary cancer is detected despite extensive diagnostic examination [1].

Clinical Perspective

CM may be completely asymptomatic or may present with non-specific visual disturbances, most commonly blurred vision. In CM from pulmonary carcinoma, ocular pain is considerably frequent. In one-third of cases, CM present concurrently with one or more distant metastases, indicating a poorer outcome [2]. Besides the choroid, the other frequent sites of pulmonary carcinoma metastases are bones, lymph nodes, liver and brain [3].

Imaging Perspective

Ocular US A-B scan defines tumour dimensions, shape, echogenicity and inner structure. On B-scan, CM are characterised by plateau or dome-shaped configuration, with minimal or absent internal vascularization and frequently accompanied by serous retinal detachment. A-scan shows medium to high lesion reflectivity. Distinctively, choroidal melanoma appears dome-shaped, may reveal vasculature on B-scan and demonstrates medium to low reflectivity on A-scan [4].

While US currently represents the gold standard in diagnosis and differentiation between different choroidal lesions, EDI-OCT is a useful tool for confirmation of the diagnosis and detection of very small lesions. Furthermore, it can be valuable in evaluation of response to treatment. CM presents as dome-shaped elevations of neurosensory retina with irregular lumpy anterior tumour surface and adjacent subretinal fluid with hyperreflective speckles [5].

Computed tomography (CT) typically demonstrates a soft tissue lesion with marked enhancement.

Magnetic resonance imaging (MRI) is the imaging modality of choice for local evaluation of orbital masses due to its superior soft tissue contrast. The typical presentation of CM is semilunar choroidal lesion that appears isointense on T1-weighted images and hypo- or hyperintense on T2-weighted images. CM can be well-defined or diffusely infiltrating in appearance. It usually shows homogeneous enhancement after contrast administration. T2-weighted images may demonstrate a retinal detachment. [6,7]

Outcome

Treatment of CM requires a multidisciplinary approach to stage the disease, identify the primary cancer and any additional metastases. Due to the advanced stage of the primary cancer, the treatment is frequently palliative. In some cases, systemic chemotherapy or specific targeted therapy are a sufficient therapeutic option. However, in cases of poor response there are several local treatment options available, mainly radiation therapy (brachytherapy), laser photocoagulation, intravitreal injections of anti-VEGF agents and enucleation [8].

Teaching points

Choroidal metastases may be a primary presentation of advanced metastatic carcinoma and require extensive imaging work-up.

Written informed patient consent for publication has been obtained.